<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>微博</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .top {
            /*为了防止背景图大于元素大小使用no-repeat top center属性可以看到主体内容*/
            background: url("../image/sina_top.png") no-repeat top center;
            height: 44px;
            width: 100%;
            position: fixed;
            top: 0;
            left: 0;
        }

        .box {
            width: 1002px;
            margin: 44px auto 0;
        }

        .ad_l, .ad_r {
            position: fixed;
            top: 100px;
        }

        .ad_r {
            right: 0;
        }

    </style>
</head>
<body>

<div class="top"></div>
<div class="box">
    <img src="../image/sina_body.png">
</div>
<img src="../image/sina-ad-l.png" alt="" class="ad_l">
<img src="../image/sina-ad-r.png" alt="" class="ad_r">
</body>
</html>